[GHC] #8647: Reduce allocations in `integer-gmp`

[GHC]

#8647: Reduce allocations in `integer-gmp`
--------------------------------------------+------------------------------
        Reporter:  hvr                      |            Owner:
            Type:  task                     |           Status:  patch
        Priority:  normal                   |        Milestone:  7.8.1
       Component:  libraries (other)        |          Version:  7.6.3
      Resolution:                           |         Keywords:  integer-
Operating System:  Unknown/Multiple         |  gmp
 Type of failure:  Runtime performance bug  |     Architecture:  x86_64
       Test Case:                           |  (amd64)
        Blocking:                           |       Difficulty:  Unknown
                                            |       Blocked By:
                                            |  Related Tickets:  #8638
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Comment (by Herbert Valerio Riedel <hvr@…>):

 In [changeset:"cbde86278d2090e19e62f0dd22682b4381433658/integer-gmp"]:
 {{{
 #!CommitTicketReference repository="integer-gmp"
 revision="cbde86278d2090e19e62f0dd22682b4381433658"
 Wrap `gmpz_fdiv_{q,r,qr}_ui` to optimize `div`/`mod`

 This is similiar to what has been done in [af2ba9c8/integer-gmp] for
 `gmpz_tdiv_{q,r,qr}_ui` (re #8647); However, the gain is more modest
 here, as performance-conscious code tends to use `quot`/`rem` rather
 than `div`/`mod`:

      Program    Size    Allocs   Runtime   Elapsed  TotalMem
  -------------------------------------------------------------
    primetest   +0.3%     -2.4%      0.06      0.06     +0.0%
          rsa   +0.2%     -3.3%      0.02      0.02     +0.0%

 Signed-off-by: Herbert Valerio Riedel <hvr at gnu.org>
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8647#comment:15>
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